Lidding and strapping machine



Feb.20, 1934. I PAX'TON T 1,947,917

LIDDING AND STRAPPING MACHINE Filed July 51. 1931- g s Sheets-Sheet 1 Haze Paxion;

20, 1934. H, PAXT 1,947,917

LIDDING AND STRAPPING MACHINE Filed July 31. 1931 3 Sheets-Sheet 2 Patented Feb. 20, 1934 1,947,917 I LIDDING AND STRAPPING MACHINE Hale Paxton, Redlands, Calif., assignor to Paxton Credit Corporation, Sanger, Calif., a corporatiton, of California Application July 31, 1931. Serial No. 554,213

19 Claims. (Cl. 140-93) My invention relates to the art of applying closures to shipping cases and particularly to a novel apparatus for lidding and strapping cases packed with farm produce, such as fruit or vegetables.

While my invention is adapted for use in many different industries, it is particularly usefulin lidding and strapping cases packed with citrus fruits, and accordingly will be described herein V in connection with this use.

In packing citrus fruits, it is customary to fill the boxes so that the contents extend above the .top thereof, press the lid onto the box so that the middle of the lid budges upwardly, then'nail the ends of the lid to the box ends and secure a strap to the box so as to tie down the middle of the lid. The pack thus produced is called a crown pack and the higher this pack is in any particular shipment of fruit the more marketable this shipment becomes, as the fuller the boxes appear to be the easier it is for the wholesaler to dispose of these to the retailers. Former strapping machines employed in strapping citrus shipping cases have deflected vthe 'side edges of the lid downwardly to such a degree as to make the crown pack appear lower than it actually is. This has resulted from the pressurable application of a lid shaper to the lid in connection with applying the strap, there being no control of the pressure thus applied to the lid.

It is an object of my invention to provide a lid strapping machine in which the pressure applied to the lid incidental to the strapping operation may be predetermined. Y

In packing certain kinds of farm products, such as lettuce and also some forms of citrus fruits, such as grapefruit, the produce, when compressed under the lid, is sufliciently resilient to expand outwardly after the lid has been strapped. In the strapping machines in common use, however, the lid istightly held down after the strap is applied so that this expansion is not permitted.

It is accordingly an object of my invention to provide a box strapping machine which will apply a strap with a predetermined space between the lid and the strap to permit expansion of the lid under the strap.

The preferred embodiment of my invention shown herein consists in an improvement of the box strapping machine shown in the application for U. S. Letters Patent of Harry D. Benson, Ser. No. 505,575, filed Dec. 30, 1930. The Bension machine employs a hydraulically operated .box

elevator. Power means are required in automatic adjustment of the strap applying means in the presentinvention.

It is accordingly a further object of my invention'to provide hydraulic means for operating the strap applying means of a strapping machine which functions cooperatively with a hydraulic box elevator thereof.

The manner of accomplishing the foregoing objects, as well as further objects and'advan tages, will be made manifest in the following description, together with the accompanying drawings, in which? Fig. 1 is a front elevational view, partially broken away, of a preferred embodiment of my invention. V

Fig. 2 is a view taken on the line 22 of Fig. 1.

Fig. 3 is a view similar to Fig. 2 to show a difierent operating position of the elements of the invention further broken away to illustrate the mechanism thereof.

Fig. 4 is an enlarged transverse sectional view taken on the line 44 of Fig. 1 to illustrate the details of ,the strapping mechanism of the invention.

Fig. 5 is an enlarged fragmentary detail sectional view taken on the line 5- 5 of Fig. 4.

Fig. 6 is an enlarged sectional view taken'on the line 6-6 of Fig. 4.

Fig. 7 is an enlarged horizontal sectional view taken on the line 77 of Fig. 4.

Fig. 8 is a fragmentary sectional view of a strapper saddle bar of my invention illustrat- 9o ing the manner in which a strap is placed in the jaws of the saddle bar when the latter is in open position.

The preferred embodiment of my invention illustrated in the drawings comprises a combined lidding and strapping machine 10 which includes a frame 11, a box elevator 12, a lid positioning and nailing mechanism 14, a strap shaping, positioning and driving mechanism 15, and a fluid control mechanism 16 for controlling the operation of the elevator 12 and the strap mechanism 15.

The frame 11 has a base 20 including feet 21 formed of heavy angle iron which are connected by heavy cross plates 22 and have channel beam standards 23 extending upwardly therefrom. Upper portions of the standards 23 are connected by a suitable connecting bar 24.

The box elevator 12 includes a hydraulic cylinder 25. into the chamber 26 of which fitted 110 a plunger 27. The cylinder 25 has an outer shell 28 formed integrally therewith and which is welded to inner faces of the plates 22in order to rigidly mount the elevator 12 on the frame 11. The space between the cylinder 25 and the shell 28 provides a reservoir chamber 30. This chamber is normally kept filled with a body of light lubricating oil 31 for a purpose which will become manifest hereinafter.

Certain pipe and valve connections are made with the cylinder 25 and shell 28 for the purpose of controlling the operation of the elevator 12, these connections being described hereinafter in connection with the fluid control mechanism 16.

Mounted on the plunger 2'7 is a box supporting table 34 having box positioning rollers 35 at its opposite ends and a pair of flanged rollers 36 which are adapted to engage flanges 3'7 of the channel standards 23 so as to guide the table 34 while being elevated or lowered on the plunger 27. The rollers 35 are spaced apart a suitable distance for snugly receiving a box or shipping case 39 packed full of fruit 40 so that the latter extends above the top of the box approximately as shown in Figs. 1 and 2.

Pivotally supported on a suitable bracket fastened on the table 34 is a roller 38 the purpose of which will be made evident in connection with the description of the fluid control means 16.

The lid positioning and nailing mechanism 14 This mechanism is mounted upon a pair of brackets which are preferably welded on the standards 23 and extend forwardly therefrom. Mounted for free rotation between a pair of brackets 46 underneath the brackets 45 is a pair of lid guiding rollers 47. Secured to the brackets 45 so as to extend downwardly and inwardly therefrom beneath the rollers 47 is a pair of spring latches 48 for receiving and supporting the lid 49 as shown in Fig. 1.

Forward ends of the brackets 45 are connected by a cross bar 53 which is shaped as shown in Fig. 1. Mounted on inner faces of each of the brackets 45 is a battery of nailing chucks 55 each of which has a hammer 56, these hammers being rigidly connected at their upper ends to a reciprocating hammer actuating frame 62. The frame 62 includes horizontal side members 63, transverse members 64 and 65, and vertical shafts 66, which are secured to the cross member 64 and slide vertically in slide bearing blocks .67 mounted on inner faces of the channel standards 23. Provided on the shafts 66 extending outwardly through openings 68 in the standards 23 are pins '70 which are connected by cross braces 71 to opposite ends of the transverse member 65. Journalled in suitable bearings provided on the lower portions of the standards 23 is a drive shaft '72 having a clutch 73 and, on its opposite ends, cranks 74 which are connected by pitmans '75 to the pins 70. The clutch 73 is provided with a trip mechanism 80 which, when actuated, throws in the clutch 73 and causes the shaft 72 to make a complete revolution and halt in its original position, this resulting in the hammers 56 going through an entire lid nailing cycle.

The strap shaping, positioning and driving mechanism 15 This mechanism is supported by a pair of angle irons 84, opposite ends of which are secured to the. transverse frame members 24 and 53. Mounted between the angle irons 84 on trunnions 86 so as to be rockable on a transverse axis is a fluid elevator cylinder 8'7. Extending into this cylinder is a plunger piston 89 having a hollow stem 90 which extends upwardly through a yoke 91 and is secured thereto by a nut 92.

The yoke 91' has legs 93 and 94 which are connected by a brace 95. Secured to the lower ends of the yoke legs 93 and 94 is a saddle bar 98 which includes a pair of plates 99 having a pair of notches 100 formed centrally in their upper edges. The plates 99 are spaced by and secured to a channel bar 101 extending along the lower edge of the saddle bar 98. The saddle bar 98 is provided with a lid shaping face 103, outer portions of which are inclined downwardly in the preferred embodiment illustrated. The channel bar 100 follows this face and has a strap shaping channel 105 as shown in Figs. 4 and 5.

The channel bar 100 is shorter than the plates 98 so that free spaces 106 are formed between opposite end portions of these plates. Secured in place in the spaces 106 between plates 99 by bolts 107 are cylindrical spacers 108. Pivotally mounted on the spacers 108'in the spaces 106 are a pair of strapper jaws 110. Each of these jaws includes a pair of plates 112 which are held in spaced relation by a bolt 113 and a spacer 114. Lower extremities of the plates 112 are turned out to form strap guides 115.

Disposed between upper extremities of the plates 112 and pivotally connected thereto by a bolt 116 is an eye 117 of a rod 118. Each of the rods 118 extends upwardly through one of a pair of slide blocks 120 pivotally mounted between the angle irons 84. Each of the rods 118 has a collar 122 near its lower end and compression springs 123 are coiled about these rods between these collars and the blocks 120. Provided on the upper ends of these rods are look nuts 125 for limiting the downward movement of the rods and the jaws to which they are pivotally connected.

Inner faces of the plates 112 of each jaw 110 are channeled out to form a driverway 128. Secured in place between the plates 112 to define boundaries of this driverway are stops 129 and Positioned in each driverway 128 and pivoted on the spacer 108 therein, is one of a pair of strap drivers 132. Each driver 132 has a lower driving head 133 and a laterally extending arm 134. Connecting the frame 62 of the lid nailing mechanism 14 to the strap driver arms 134 is a pair of yieldably extensible links 138. Each link 138 includes a cylinder 139, the lower end of which is pivoted to one of the arms 134. This cylinder has. a piston 145 which is connected to a piston rod 146, this rod extending upwardly through a head 147 of the cylinder, and being pivotally connected to one of the bars 64 or of the reciprocating frame 62. Each piston 145 is provided with a packer 150 which faces downwardly and a suitable by-pass is provided in the piston rod 146 which is adapted to conduct fluid through the piston 1.45 at a relatively slow rate when this piston is moved downwardly in the cylinder 139.

Disposed between'the piston 145 and the head 147 of each of the links 138 is a compression spring 155 which continuously urges the cylinder 139 upwardly and lifts the driver arm 134 to which this link is connected, thus bringing the head 133 of this driver against its stop 129. The cylinder 139 of each of the links 138 is preferably filled with oil.

This mechanism is adapted for controlling the operation of the elevator 12 and the strap shaping, positioning and driving mechanism 15, and includes a pump 160 which is continuously operated by the motor (not shown) which is connected'to the clutch 73 for the purpose of rotating this. The pump 160 has an intake pipe 161 which connects with the lower end of the reservoir 30. Provided on the shell 28 and extending therethrough so as to connect with the cylinder 25 and open into the lower end ofthe cylinder chamber 26 is an elevator check valve 162. This valve has a stem 163 which, if depressed, opens the check valve 162 and permits fluid to flow outwardly from the cylinder chamber 26 through this valve. Connecting with the upper end of the reservoir 30 is a control valve 165 which is normally spring-pressed into open position, this valve having a stem 166 which, when depressed, closes the valve. Provided on the shell 28 and also connecting with the reservoir 30 is a check valve 168 which is normally spring-pressed into. closed position so as to prevent fluid being forced into this reservoir but which is adapted to be opened by depressing a stem 169 provided on the valve. Connecting the valve 162 with the valve 165 is a pipe 170- which in turn is connected by a pipe 171 to the discharge end of the pump 160.

Pivoted on the rearmost of the plates 22 is a bell crank 172 having an eye 173 formed in its upper end and which is juxtaposed relative to stems 163 and 169 of the valves 162 and 168 so that rotation of the bell crank 172 in a clockwise direction, as shown in Fig. 2, positively opens these valves. Pivotally mounted in suitable brackets provided on the foremost of the plates 22 is a pair\of shafts 175 and 176 having foot pedals 177 and 178 secured thereto respectively. On opposite ends of these shafts are provided arms 179 and 180 respectively, the arm 179 being connected by a link 181 to the upper end of the bell crank 172.

Pivoted on a bracket 182 provided on the 'valve 165 is a valve operating lever 183, the front end of this being connected by a link 184 to the pedal arm 180. Hanging from the rear end of the arm 183 is a link 185 having an eye 186 on its lower end, this being approximately opposite the eye 173 of the bell crank 172.

Fixed upon the shaft 172 is an eccentric 187 having a band 4% from which a rod 189 extends so as to pass through the eye 186 and the eye 173. Suitable collars 190 are provided on the rod 189 to position the eye 186 longitudinally on this rod. The rod 189 has an end portion thereof machined away to provide a /Sh0l1ld81"191 thereon. Whenever the shaft 72 is 0 in its normal position of rest the eccentric 187 extends forward as shown in Figs. 2 and 3. When, at this time, the shoulder 191 .of the rod 189 is lifted out of engagement with the bell crank 172, the springs in the valves 162 and 168 extend the stems 163 and 169 thereby rotating the bell crank 172 into the position in which it is shown in Fig. 3- and closing these valves.

This movement of the bell crank, of course,

swings the arm 179 so as to lift the pedal 177 away from thefloor.

Lifting of the rod 189 with the results thus described takes place whenever the pedal 178 is depressed (as shown in Fig. 3) in order to swing the lever 183 and close the valve 165.

Leading from the check valve 168 is a strapper elevator exhaust pipe 192, the upper end of which is supported on a bracket 193 provided on the adjacent standard 23. Leading from the pipe 170 is a strapper elevator pressure fluid pipe 194 having an auxiliary pressure pipe 195,

the pipes 194 and 195 also having their upper ends supported by the bracket 193. The pipe 195 is provided with a valve 196 which is normally held in closed position as shown in Fig. 2 by a spring 197. Slidably mounted on the outer face of the adjacent standard 23 is a cam 189 which lies in the path of the roller 38. When the cam 198 is contacted by the roller 36 during vertical movement of the elevator 12, the valve 196 is opened, this valve being closed immediately by the spring 197 as the roller 36 passes out of contact with the cam 198.

Referring now particularly to Figs. 3, 4, 5 and 7, there is seen to be provided on the arm 93 of the strapper yoke 91 avalve manifold 200 having an inner chamber 201 which is provided medially with a check valve 202. Connecting the upper end of this chamber with the upper end of the exhaust pipe 192 is an exhaust hose 203. Connecting the lower end of the chamber 201 with the upper end of the auxiliary fluid pressure pipe 195 is a hose 204. Also leading from the upper end of this chamber is a pipe 205 which connects with the stem 90 of the plunger 89 so as to place the upper end of the chamber 201 in constant communication with the interior ofthe strapper elevator cylinder 87. Provided in the lower end of the manifold 200 is a slide valve 208 which connects with the lower end of the chamber 201 and is supplied with fluid through a hose 209 which leads from the fluid pressure pipe "194. The valve 208 is provided with a plunger 210 which is constantly urged by a spring 211 into closed position so as to shut off the supply of fluid from the hose 209 to the chamber 201. The plunger 210 has a stem 212 extending downwardly through a suitable packing gland 213 provided in the body of. the valve 208. Mounted on the lower end of the stem 212 is an antifriction roller 214 which is adapted to beengaged by one end of a lever 215 to open the valve 208. The opposite end of the lever 215 is pivoted at 216 on the yoke' 91. The lever 215 has an enlarged middle portion 220 provided with a central opening 221 and a transverse knife edge 222 which faces downwardly.

Disposed on opposite sides of the saddle bar 98 are side plates 225 of a lid responsive member 226, the plates 225 having slots 227 through which cap screws 228, screwed into the saddle bar 98, extend. The plates 225 are connected centrally by a head 230 having an opening 231, the head 230 being adapted to move up and down in the notches 100 formed in the saddle bar plates 99. -Lower edges of the plates 225 conform generally to the shape of the lower face 103 of the saddle 98 and extend slightly below the face 103. Formed centrally in lower edges of the plates 225 are hand notches 233. Trapped in the opening 231 so as to be rotatable therein on a vertical axis is a spool shaped nut 238. Threadedly received by the nut 238 is a pusher rod 239 having a head 240 formed on its lower end normally resting on top of the strap shaping bar 101. Screwed onto the rod 239 just above the nut 238 is a lock nut 242, the function of which is to flx the nut 238 in adjusted position on the push rod 239. The push positioned as shown in Figs. 1 and 2.

end, the diameter of which is reduced to provide an annular shoulder 246 on the rod 239. The stem 245 extends through the opening 221 in the large portion220 of the lever 215 so that the knife edge 222 of this lever normally rests upon the shoulder 246 when the push rod head 240 rests upon the strap shaping bar 101 and the free end of the lever 215 is just in contact with the roller 214 with the valve 208 closed.

Threadedly received on the stem 245 is a nut 248 which is surmounted by a cup washer 249 and disposed between this washer and the cross bar 95 of the yoke 91 is a compression spring 250. The nut 248 is adapted to be adjusted on the stem 245 to place a selective amount of pressure downwardly against the push rod 239 so as to resist the head 240 of this rod being lifted from contact with the strap shaper bar 101. When the rod 239 is thus lifted the lever 215 presses upwardly on the roller 214 so as to open the, valve 208.

Operation The operation of my invention is as follows:

At the beginning of a cycle of operation of the machine 10, the parts of the machine are Here it is seen that the check valves 162 and 168 are open as' a result of engagement by the shoulder 191 on the rod-189 with the bell crank 172. This relieves pressure from the fluid in the strapper elevator cylinder 87 so that this fluid is free to pass therefrom through the pipe 205, hose 203, pipe 192 and valve 168 into the oil reservoir 30.' The piston plunger 89 of the strapper elevator and the saddle bar 98 attached thereto thus drop down so that the jaws 110 swing outwardly into their open position in which they are shown in Fig. 2.

With the jaws in this position a strap 260 is moved upwardly into place as shown in Fig. 8, pointed ends 261 of the strap coming to rest on the spacers 114 of the jaws 110.

A lid 49 is now lifted up so that the ends spring into position inside the spring latches 48 in a position as shown in Fig. 1. The box 39 filled with fruit 40 1s now placed on the elevator 12 as shown in this figure and the pedal 178 depressed by the operator. As before stated, the pump 160 =is in constant operation and,

while the machine 10'is standing idle, a circu-' lation of fluid is setup-by the pump through the pipe 171 into the pipe 170, through tlie valve 165 into the reservoir 30, and thence, returning to the pump from this reservoir through the a pipe 161.

During the time the pedal 178 is depressed, the valve 165 is held closed so that the fluid expelled by the pump 160 into the pipe 170 must either go up the pipe 194 or must go through the valve 162 into the bottom end of the box elevator cylinder chamber 26. 5

As the valves 196 and 208 controlling the outlet of oil through the pipe 194 are now closed, this oil is forced through the valve 162 into the chamber 26 and causes the elevator 22 to rise. The depression of the pedal 178 also lifts the arm 186 as described hereinabove so as to lift the rod 192 to permit the bell crank 172 to be swung by the springs in the valves 162 and 168 so that these valves become spring check valves preventing exhaust of fluid from the box elevator chamber 26 and the strapper elevator 87, respectively.

At the point in the upward movement of the elevator 12 where the upper end of the box 39 reaches such a height that the jaws 110, when swung downwardly, will engage the side of the box, the roller 38 comes in contact with the cam 198 so as to open the valve 196. Owing to the closing of the valve 165 to cause the box elevator to rise, a pressure of fluid has been set up in the pipes 170 and 194 so that whenthe valve 196 is thus opened fluid under pressure is expelled through the hose 204 into the chamber 201 of the control manifold 200, this fluid passing upwardly through the check valve 202 and into the strapper elevator cylinder 87. The time and amount which the valve 196 is thus open is calculated to allow just enough fluid to pass into the cylinder 87 to lift the saddle bar 98 the distance shown in Fig. 3 whereby the jaws 110 are swung downwardly into contact with the sides of the rising box, thus preshaping the strap 260 in readiness to be applied to the box 39. After the roller 38 leaves contact with the cam 198 the valve 196 is of course instantly closed by the spring 197.

After the preshaping of the strap in the manner just described, the pedal 178 is still held down until the elevator continues upwardly to the point where the ends of the box 39 come into engagement with the cleated ends of the lid 49 and force these upwardly against the lower faces of the nail chucks 55. The valve 165 is so arranged that when upward movement of the elevator 12 has thus been halted the excessive pressure set up by the pump 160 will force fluid through the valve 165 into the reservoir 30.

The operator now removes his foot from the pedal 178 and actuates the control mechanism for nailing and strapping the lid 49 to the box 39. Before describing this operation, however, the manner in which the control mechanism 16 functions to position the preshaped strap relative to the lid 49 of the box 39 will be described.

The strapping mechanism 15 is supported at such a height that while the. ends of the lid 49 are yet some distance below the lower ends of the chucks 55, the middle portion of this lid comes in contact with the lower edges of the side plates 225 of the lid responsive member 226. When the pressure of the lid against the member 226 becomes suflicient to compress the spring 250 the lever 215 is raised to open the valve 208 and allow fluid under pressure from the hose 209 to pass upwardly through the manifold 200 into the cylinder 87 so as to lift the saddle bar 98 and prevent a pressure in excess of that necessary to open the valve 208 from being imposed by the saddle bar upon the lid. As soon as sufilcient fluid is admitted through the valve 208 to lift the saddle bar 98 so as to relieve the excess of pressure between the lid 49 and the lid responsive member 226, the spring 250 expands, swinging the lever 215 downwards, thus shutting the valve 208 and stopping upward movement of the saddle bar 98.

It is thus seen that by adjustment of the nut 248 on the stem 245 so as to vary the compression of the spring 250, the amount of resistance by the lid responsive member 226 to upward movement of the middle portion of the lid 49 may be accurately predetermined. Whenever this pressure of the lid against the lid responsive member 226 is such as to overcome the'pressure of the spring 250 the valve 208 is operated to lift the entire strapper mechanism 15 upward sufilciently to decrease this pressure so that it does not exceed the predetermined amount.

This automatic adjustment of the strapper mechanism 15 to the lid 49 takes place during the latter portion of the upward movement of the elevator 12 so that when the upper point in this movement is reached the lid 49 is not only positioned with its ends beneath the chucks 55 ready to be nailed to thebox 39, but the middle of the lid is subjected to exactl the desired amount of pressure to properly bow the lid without crushing the fruit therebeneath.

The time required for the automatic adjustment of the strapping means 15, as just described, is so short that when this box comes to rest, he control mechanism may be immediate \engaged to cause the lidding and strapping of the box. The latter function is performed by a single rotation of the shaft 72 and involves a single downward and upward reciprocation of the overhead frame 62.

The yieldable extensible links 138 are provided to compensate for the saddle 98 being lifted different heights by different sized boxes 39 or different amounts of fruit piled thereon.

When the frame 62 is stationary in its upward position the springs 155 of the links 138 urge the cylinders 139 upward so as to retain the heads 133 of the drivers 132 pressed outwardly against the stops 129 even though in the preliminary adjustment of the saddle bar 98 and associated parts the drivers 132 are actually lifted relative to the reciprocating frame 62.

Operation of the springs 155 to maintain this condition during the preliminary adjustment is possible owing to the relatively slow speed with which this adjustment is made so that the fluid displaced by the pistons 145 in this adjustment has ample time to flow through the by-passes in the stems 146.

Nailing of the ends of the lid 49 to the box 39 is accomplished by the driving of a nail from each chuck 55 through the lid into the box when the frame 62 reciprocates as before described. With the same'movement of the frame 62 which thus lids the box, the piston rods 146 of the extensible links 138 are suddenly moved downwardly. This motion does not give time for the escape of,liquid from in front of the pistons 145 so that the drivers 132 are swung downwardly driving the pointed ends 261 of the strap 260 into the box 39.

It is to be noted here that a considerable component of the downward pressure against the drivers 132 is applied to the spacers 108, about which these drivers rotate, and is transmitted by these spacers to the saddle bar 98. This pressure, if downward, and were it not for the fact that liquid at this time is trapped in the cylinder 87 so as to prevent any downward movement of the saddle bar, would increase the pressure between the saddle bar and the lid.

During the first part of the rapid upward return of the reciprocating frame 62 the driver heads 133 are returned into contact with the stop The single rotation of the shaft 72 to accomplish the nailing and lidding operation rotates the eccentric 187 to pull the rod 189 backwards through the eye 173 until the shoulder 191 of the rod drops in place opposite the lower end of the eye 173, after which the return of the ec centric 187 to normal position swings the bell crank 172 into the position in which it is shown in Fig. 2 so as to open the check valves 162 and 168 permitting fluid to be exhausted from the elevator cylinders 25 and 87 respectively. This allows the elevator 12 and the saddle bar 98 to move downwardly simultaneously to their lowermost positions in which they are shown in Figs. 1 and 2. This movement of the saddle bar of course swings the jaws 110 outwardly in readiness for receiving another strap to be applied in the next following strapping operation.

When the elevator is lowered, the roller 38 engages the cam 198 as on its upward .travel and opens the valve 196, but this has no effect, as the oil in the pipe 194 is not at thistime under pressure owing to the fact that the foot pedal 178 has previously been released allowing the valve 165 to open.

The box 39 is now removed from the elevator 12 completely lidded and strapped and another box placed on the elevator preparatory to the next lidding and strapping operation, which is accomplished in exactly the same manner as that above described for the box 39.

In some instances, cases of fruit are lidded and strapped as above described, in which the fruit or other contents of the case are relatively resilient and it is desired that the lid be free to expand a certain amount after the strap has been applied to the box. The adjustment of the nut 238 determines the distance from the lid 49 which the strap 260 is placed just before the ends of the strap are driven into the box 39. It is thus seen that I have provided not only a means for predetermining the pressure applied to the lid when the box is strapped, but also a means for predetermining the distance which the lid is disposed from the strap at the time the strap is secured to the box.

Attention is also directed to the fact that the strap mechanism 15 is supported by liquid in the cylinder 87 during the driving of the strap ends into the box so that downward pressure applied to the drivers 132 is not transmitted through the saddle bar 98 to the lid.

While I have shown and described but a single embodiment of my invention it is understood that various changes and modifications might be made in this without departing from the spirit of the invention or the scope of the appended claims.

I What I claim is:

1. In a box strapping machine, the combination of: a saddle'for contacting a lid positioned on a box; means for bringing said saddle and said lid together; strap positioning and securing means provided on said saddle;. and means for automatically controlling the pressure with which said saddle and said lid are brought together.

2. In a box strapping machine, the combination of: a saddle for contacting a lid positioned on a box; means for bringing said saddle and said lid together; strap positioning and securing means provided on said saddle; and means for automatically controlling the interval between the shaped portion of said lid and said strap when the latter is secured to said box.

3. In a machine for strapping lids on boxes, the combination of means for shaping and positioning a strap having driving ends across said lid, with said strap ends adjacent opposite side faces of said box; means for correspondingly shaping said lid and the portion of said strap adjacent thereto; means for driving the ends of said strap into said box; and means for predetermining the amount of pressure with which said lid is shaped prior to the securing ofsaid strap to said box.

4. In a machine for strapping lids on boxes, the combination of: means for shaping and positioning a straphaving driving ends across said lid, with said strap ends adjacent opposite side faces of said box; means for correspondingly shaping said lid and the portion of said strap adjacent thereto; means for driving the ends of said strap into said box; and means for predetermining the space between said lid when shaped and said strap when positioned for securing to said box.

5. A combination as in claim 3 in which said strap shaping and positioning means shapes said strap prior to positioning it for securing to said box.

6. A combination as in claim 4 in which said strap shaping and positioning means shapes said strap prior to positioning it for securing to said box.

7. In a machine for strapping lids on boxes, the combination of strapsupporting, shaping and securing means; box supporting means; means for bringing said aforementioned means towards each other; and fluid power means controlled by the approach of said strap means and said box supporting means to cause said strap means to shape said strap for application to said box prior to the contact of said strap means and the lid of said box.

8. In a machine for strapping lids on boxes, thecombination of: strap supporting, shaping and securing means; box supporting means; means for bringing said aforementioned means towards each other; power means to cause said strap means to shape said strap for application tosaid box prior to the contact of said strap means and the lid of said box; and means for controlling movement of one of the first two above mentioned means, said control means being operated by contact with the lid of said box so as to regulate the pressure with which said strap means contacts said lid.

9. In a machine for strapping lids on boxes, the combination of: box supporting means; means for positioning a strap adjacent to the lid of said box to permit the ends of the strap to be secured to the box with the strap disposed transversely across the lid; power means for causing relative movement of said box supporting means and said strap positioning means towards and away from each other; a control member associated with said strap positioning means so as to be brought into contact with said lid when said power means brings said box supporting means and said strap positioning means toward each other, said control member controlling said power means to regulate the pressure between said control member and said lid.

10. A combination as in claim 9 in which means are provided for mounting said control member on said strap positioning means for adjustment so that said strap is positioned in a spaced relation relative to said lid which is predetermined by said adjustment.

11. A combination as in claim 9 in which means areprovided for mounting said control member on said strap positioning means for adjustment to require a certain amount of pressure by said lid against said control member to power means operates through a fluid and includes a fluid elevator for said box supporting means and a fluid elevator for said strap positioning means and in which said control member causes said strap positioning means elevator to lift said strap positioning means to relieve pressure between said control member and the lid of said box.

13. In a machine for strapping lids on boxes, the combination of: a box supporting platform; a fluid power elevator therefor; strapper means suspended over said elevator and adapted to receive a strap and support this in position to be applied to the lid of said box to permit the ends of the strap to be secured to the box with the strap disposed transversely across the lid; a fluid elevator for said strapper means; a control member actuated in conjunction with the rising of said box elevator to cause said strapper means elevator to lift said strapper means to shape said strap for application to said box prior to contact between the lid of said box and said strapper means; a second control member adapted to be contacted by said lid to control said 105 strapper means elevator to cause it to lift said strapper means when the pressure between said lid and said second control member has reached a predetermined value.

14. In a machine for strapping lids on boxes, 110 the combination of: a box supporting platform;

a fluid power elevator therefor; strapper means suspended over said elevator and adapted to receive a strap and support this in position to be applied to the lid of said box to permit the ends v of the strap to be secured to the box with the strap disposed transversely across the lid; a fluid elevator for said strapper means; a control member actuated in conjunction with the rising of said box elevator to cause said strapper means elevator to lift said strapper means to shape said strap for application to said box prior to contact between the lid of said box and said strapper means; a second control member adapted to be contacted by said lid to control said strapper means elevator to cause it to lift said strapper means when the strap is spaced a predetermined distance from said lid.

15. A combination as in claim 13 including means for securing the ends of said strap to said 180 box; and means operated by said strap securing means to permit the discharge of fluid from said elevators upon the completion of a strapping operation. I

16. In a box strapping machine the combination of: means for automatically shaping transversely'a-middle portion of the cover of an overfilled box and positioning a strap across said tion in spaced relation therewith; means for automatically regulating the pressure with which said'shaping is efiected to keep this uniform despite variationsin the height of said middle portion of said cover; and means for securing ends of said strap to sides of said box.

18. In a box strapping machine the combina tion of: means for automatically shaping transversely a middle portion of the cover of an overfilled box; means for shaping a strap to substantially conform to the shape of said cover and positioning said strap across said cover por- I tion in spaced relation therewith; means for pretermining the distance separating said cover and said strap when the latter has been so positioned; and means for securing ends of said strap to sides of said box.

19. In a box strapping machine the combination of: means for automatically shaping translating the pressure with which said shaping is effected to keep thisuniform despitevariations in the height of said middle portion of said cover; and means for securing ends or said strap to sides of said box.

HALE PAXTON. 

